1. Field of the Invention
The present invention relates to elevator performance measuring devices, and more particularly to a self-contained, portable microprocessor system designed to analyze elevator performance in real time and report specific points of information, as they occur in real time, in a easily readable alphanumeric format.
2. Description of the Related Art
Qualitative elevator performance analysis is extremely important to professionals in the elevator industry. Elevator performance analysis is typically done with expensive ride analysis systems. There are two categories of ride analysis systems: portable systems; and fixed systems. Fixed systems are limited to use with a single elevator and always require down time for installation and removal. Portable systems have the advantage of being useful in multiple elevators but are expensive and difficult to operate. Also, most analysis systems, fixed or portable, require a separate computer for analyzing the recorded data.
Because of the cost of the common analysis systems many professionals use alternate methods of analysis that are subjective and inaccurate. The alternate methods use tachometers or stop watches to measure elevator speed. Rate values and jerk values cannot be measured in this manner so these values are commonly left undetermined. Also, many of these methods are unsafe because they require the user to access the elevator pit, hoist way or elevator car top to take the measurements.
The following patent documents disclose systems and devices for measuring the performance of an elevator.
U.S. patent application No. 2003/0121730 published on Jul. 3, 2003 for Liu et al. discloses a condition-base, auto-thresholded elevator maintenance system. The system generates variable thresholds in response to an average defect rate that is generated under certain conditions. Any excess defects set off an internal flag. The internal flag can then generate a maintenance flag that results in a maintenance recommendation for the particular parameter having the defects.
U.S. Pat. No. 4,002,973 issued on Jan. 11, 1977 to Wiesendanger et al. discloses an elevator testing system. The system is removably connected to a control of an elevator system and selectively operated to perform a number of testing sequences. The system provides a number of artificial control signals characteristic of an operating condition for controlling the operation of the elevator system under test conditions. The system is used in a testing sequence with elevator systems employing gated rectifying circuits to accurately monitor gate pushes and other operating functions.
U.S. Pat. No. 4,330,838 issued on May 18, 1982 to Yoneda et al. discloses an elevator test operation apparatus for a multi-floor service elevator. The apparatus comprises a digital computer for processing an elevator control signal. The digital computer stores an elevator operation control program and an interface means for transferring a signal from an elevator control system to the digital computer. The elevator test system further comprises a means for generating test signals and an interface means for transferring those test signals to the digital computer. The system also provides a means for storing various programs for shortening the opening time of the elevator during testing and for establishing the elevator car weight.
U.S. Pat. No. 4,458,788 issued on Jul. 10, 1984 to LePore discloses an analyzer apparatus for evaluating the performance of an elevator transportation system that has a plurality of elevators. The system has a plurality of event accumulator devices and interconnected interface circuits. The interface circuits are each connected to a system component to be monitored and each provides an output signal indicative of the current status of its monitored system component. The accumulator devices accumulate event duration counts as a function of the monitored component current status signals from its interface circuit.
U.S. Pat. No. 4,512,442 issued on Apr. 23, 1985 to Moore et al. discloses methods and apparatus for improving the servicing of an elevator system. The methods are based upon the actual usage of the elevator functions. The usage of predetermined functions is monitored and data is collected. Threshold and limit parameters are provided for the monitored functions and are periodically compared with the usage data. When a threshold value is reached for a particular function a maintenance service is added to a maintenance due list.
U.S. Pat. No. 4,930,604 issued on Jun. 5, 1990 and European Patent Application No. 0 367 388 published on May 9, 1990 to Schienda et al. disclose an elevator diagnostic monitoring apparatus. The apparatus is connected by a serial communication link to at least one computer-based elevator controller in order to monitor the diagnostic output of each connected controller. The diagnostic output of a controller is determined by the normal operating states of the elevator. Any deviations from the normal operating states generate diagnostic messages that are communicated from the controller to the monitoring apparatus.
U.S. Pat. No. 5,027,299 issued on Jun. 25, 1991 to Uetani discloses an apparatus for testing the operation of system components such as elevator cages which has a central processor and stored control programs. The apparatus includes programs that produce diagnostic results and are incorporated with the stored control programs for controlling and operating the system.
U.S. Pat. No. 5,042,621 issued on Aug. 27, 1991 to Ovaska et al. discloses a method and apparatus for the measurement and tuning of an elevator system. The method uses a computer connected to the system. The elevator system is measured and tuned using virtual measuring and tuning components operated by programs of the computer.
U.S. Pat. No. 5,787,020 issued on Jul. 28, 1998 to Molliere et al. discloses a procedure and an apparatus for analyzing elevator functions and detecting deviating functions. An analyzer connected to the elevator learns the normal operation of each elevator independently. Signals occurring during operation are compared with the information thus acquired and a failure alarm is produced or the information is altered to in accordance with the new situation.
International Patent Application No. WO 01/14237 published on Mar. 1, 2001 discloses a device for monitoring an operation of an elevator car. The device includes a measuring unit for measuring the value of predetermined parameters and a processing unit for analyzing the measured parameter values.
U.S. Pat. No. 5,522,480 issued on Jun. 4, 1996 to Hoffman discloses a measurement pick-up to detect physical characteristics of a lift for people or freight. A portable transducer is used to detect physical parameters of an elevator including acceleration and time values. The transducer comprises a sensor, a timer associated with the sensor and a memory unit. The transducer may be connected to an external evaluation unit to download data after the testing is complete.
U.S. Pat. No. 5,817,994 issued on Oct. 6, 1998 to Fried et al. discloses a remote fail-safe control for an elevator. The remote control arrangement includes a wireless transmitter and a wireless receiver that is coupled to an elevator controller. The receiver is detachably connected to wiring that leads to the controller.
The measurement of vertical velocities, accelerations, jerk and run duration is necessary for the installation, maintenance and inspection of passenger and freight elevator systems in order to ensure safe operation of such devices and the safety of those persons which would work or travel on such devices. The measurement of these physical properties can be accomplished utilizing a digital processing device containing a single sensor that is sensitive to accelerations along a vertical axis by placing the device within an elevator car and executing a single floor-to-floor run. This device should be self contained and portable to preclude the necessity of removing the elevator from service, installing any device onto the elevator mechanism, or making alterations to the elevator to perform the measurements. The device should perform the measurements in a manner that eliminates the introduction of human error and opinion. The device should work on any type of elevator and should present the results of the measurements instantly in a format that is recognizable by the common person without the need for specialized training or detailed analysis of a time/amplitude graph.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus an elevator performance meter solving the aforementioned problems is desired.